The invention relates to a fuel container for a motor vehicle having a plurality of chambers for collecting fuel, having a fuel feeding unit whose feeding capacity can be regulated, having suction jet pumps which are arranged in at least some of the chambers of the fuel container and have the purpose of feeding fuel to the feeding unit, having a propellant line which leads from the pressure side of the fuel feeding unit to the suction jet pump, having a filling level sensor for acquiring the filling level of fuel, and having a control unit for evaluating the signals of the filling level sensor and for actuating the feeding unit.
Such fuel containers are usually designed as a saddle tank and are known from practice. In this context, the suction jet pumps are used to feed the fuel from the corresponding chamber to the feeding unit or to the chamber holding the feeding unit. The feeding unit frequently has a surge chamber which can be filled by a further suction jet pump and has the purpose of collecting fuel. It is already known to regulate the feeding capacity of the feeding unit as a function of signals of a pressure regulator which is arranged in the forward feed line, and thus as a function of the consumption of the fuel, in order to avoid unnecessarily pumping fuel around the fuel container. However, even when there is particularly low consumption, the feeding unit must maintain the feeding of fuel to the suction jet pumps, and thus ensure a minimum feeding capacity. This is generally achieved with a minimum pump rotational speed. As the number of chambers increases, the minimum feeding capacity rises since the number of suction jet pumps also rises.
A disadvantage with the known fuel container is that a large amount of fuel is moved to the fuel container as a result of the feeding capacity of the feeding unit which is defined by the number of suction jet pumps. In addition, when a fuel container is virtually empty, all the suction jet pumps are supplied with fuel via the propellant lines, even if there is no fuel present in the respective chamber. This movement leads to the formation of foam and to increasing vaporization of the fuel, which results in a high level of permeation of the fuel into the surroundings of the fuel container.
The invention is based on the problem of designing a fuel container of the type mentioned at the beginning in such a way that the movement of fuel is kept as low as possible.